Graphene Field Effect Biosensor for Concurrent and Specific Detection of SARS-CoV-2 and Influenza

The SARS-CoV-2 pandemic has highlighted the need for devices capable of carrying out rapid differential detection of viruses that may manifest similar physiological symptoms yet demand tailored treatment plans. Seasonal influenza may be exacerbated by COVID-19 infections, increasing the burden on healthcare systems. In this work, we demonstrate a technology, based on liquid-gated graphene field-effect transistors, for rapid and ultraprecise detection and differentiation of influenza and SARS-CoV-2 surface protein. Most distinctively, our device consists of 4 onboard graphene field-effect electrolyte-gated transistors arranged in a quadruple architecture, where each quarter is functionalized individually (with either antibodies or chemically passivated control) but measured collectively. Our sensor platform was tested against a range of concentrations of viral surface proteins from both viruses with the lowest tested and detected concentration at ∼50 ag/mL, or 88 zM for COVID-19 and 227 zM for Flu, which is 5-fold lower than the values reported previously on a similar platform. Unlike the classic Real-Time Polymerase Chain Reaction (RT-PCR) test, which has a turnaround time of a few hours, our technology presents an ultrafast response time of ∼10 seconds even in complex media such as saliva. Thus, we have developed a multi-analyte, highly sensitive, and fault-tolerant technology for rapid diagnostic of contemporary, emerging, and future pandemics.